Microbial-induced carbonate precipitation effectively prevents Pb2+ migration through the soil profile: Lab experiment and model simulation.

Due to the inappropriate disposal of waste materials containing lead (Pb) and irrigation with sewage containing Pb, the migration of Pb2+ within the soil profile has been extensively investigated. The conventional Pb2+ block method is challenging to implement due to its complex operational procedures and high construction costs. To address this issue, this study introduces the microbial-induced carbonate precipitation (MICP) technique as a novel approach to impede the migration of Pb2+ in the soil profile. Soil acclimatization with urea resulted in an increased proportion of urease-producing microorganisms, including Bacillus, Paenibacillus, and Planococcaceae, along with heightened expression of urea-hydrolyzing genes (UreA, UreB, UreC, and UreG). This indicates that urea-acclimatized soil (Soil-MICP) possesses the potential to induce carbonate precipitation. Batch Pb2+ fixation experiments confirmed that the fixation efficiency of Soil-MICP on Pb2+ exceeded that of soil without MICP, attributed to the MICP process within the Soil-MICP group. Dynamic migration experiments revealed that the MICP reaction transformed exchangeable lead into carbonate-bound Pb, effectively impeding Pb2+ migration in the soil profile. Additionally, the migration rate of Pb2+ in Soil-MICP was influenced by varying urea amounts, pH levels, and pore flow rates, leading to a slowdown in migration. The Two-site sorption model aptly described the Pb2+ migration process in the Soil-MICP column. This study aims to elucidate the MICP biomineralization process, uncover the in-situ blocking mechanism of MICP on lead in soil, investigate the impact of Pb on key genes involved in urease metabolism, enhance the comprehension of the chemical morphology of lead mineralization products, and provide a theoretical foundation for MICP technology in preventing the migration of Pb2+ in soil profiles.

An integrated data analysis reveals distribution, hosts, and pathogen diversity of Haemaphysalis concinna.

BACKGROUND: Haemaphysalis concinna, carrying multiple pathogens, has attracted increasing attention because of its expanded geographical range and significant role in disease transmission. This study aimed to identify the potential public health risks posed by H. concinna and H. concinna-associated pathogens. METHODS: A comprehensive database integrating a field survey, literature review, reference book, and relevant websites was developed. The geographical distribution of H. concinna and its associated pathogens was illustrated using ArcGIS. Meta-analysis was performed to estimate the prevalence of H. concinna-associated microbes. Phylogenetic and geographical methods were used to investigate the role of birds in the transmission of H. concinna-associated microbes. The potential global distribution of H. concinna was predicted by ecological niche modeling. RESULTS: Haemaphysalis concinna was distributed in 34 countries across the Eurasian continent, predominantly in China, Russia, and Central Europe. The tick species carried at least 40 human pathogens, including six species in the Anaplasmataceae family, five species of Babesia, four genospecies in the complex Borrelia burgdorferi sensu lato, ten species of spotted fever group rickettsiae, ten species of viruses, as well as Francisella, Coxiella, and other bacteria. Haemaphysalis concinna could parasitize 119 host species, with nearly half of them being birds, which played a crucial role in the long-distance transmission of tick-borne microbes. Our predictive modeling suggested that H. concinna could potentially survive in regions where the tick has never been previously recorded such as central North America, southern South America, southeast Oceania, and southern Africa. CONCLUSIONS: Our study revealed the wide distribution, broad host range, and pathogen diversity of H. concinna. Authorities, healthcare professionals, and the entire community should address the growing threat of H. concinna and associated pathogens. Tick monitoring and control, pathogen identification, diagnostic tools, and continuous research should be enhanced.

Comorbidity increases the risk of pulmonary tuberculosis: a nested case-control study using multi-source big data.

BACKGROUND: Some medical conditions may increase the risk of developing pulmonary tuberculosis (PTB); however, no systematic study on PTB-associated comorbidities and comorbidity clusters has been undertaken. METHODS: A nested case-control study was conducted from 2013 to 2017 using multi-source big data. We defined cases as patients with incident PTB, and we matched each case with four event-free controls using propensity score matching (PSM). Comorbidities diagnosed prior to PTB were defined with the International Classification of Diseases-10 (ICD-10). The longitudinal relationships between multimorbidity burden and PTB were analyzed using a generalized estimating equation. The associations between PTB and 30 comorbidities were examined using conditional logistic regression, and the comorbidity clusters were identified using network analysis. RESULTS: A total of 4265 cases and 17,060 controls were enrolled during the study period. A total of 849 (19.91%) cases and 1141 (6.69%) controls were multimorbid before the index date. Having 1, 2, and ≥ 3 comorbidities was associated with an increased risk of PTB (aOR 2.85-5.16). Fourteen out of thirty comorbidities were significantly associated with PTB (aOR 1.28-7.27), and the associations differed by sex and age. Network analysis identified three major clusters, mainly in the respiratory, circulatory, and endocrine/metabolic systems, in PTB cases. CONCLUSIONS: Certain comorbidities involving multiple systems may significantly increase the risk of PTB. Enhanced awareness and surveillance of comorbidity are warranted to ensure early prevention and timely control of PTB.

Systematic review and integrated data analysis reveal diverse pangolin-associated microbes with infection potential.

There has been increasing global concern about the spillover transmission of pangolin-associated microbes. To assess the risk of these microbes for emergence as human pathogens, we integrated data from multiple sources to describe the distribution and spectrum of microbes harbored by pangolins. Wild and trafficked pangolins have been mainly recorded in Asia and Africa, while captive pangolins have been reported in European and North American countries. A total of 128 microbes, including 92 viruses, 25 bacteria, eight protists, and three uncharacterized microbes, have been identified in five pangolin species. Out of 128 pangolin-associated microbes, 31 (including 13 viruses, 15 bacteria, and three protists) have been reported in humans, and 54 are animal-associated viruses. The phylogenetic analysis of human-associated viruses carried by pangolins reveals that they are genetically close to those naturally circulating among human populations in the world. Pangolins harbor diverse microbes, many of which have been previously reported in humans and animals. Abundant viruses initially detected in pangolins might exhibit risks for spillover transmission.

[Research Progress on the Remediation Technology of Herbicide Contamination in Agricultural Soils].

Asthe most-used pesticides in the agricultural production process, herbicides are mainly applied to protect crops from weeds. However, with the increased global demand for food, the dosage of herbicides is rising annually, and the efficacy of herbicides is getting stronger, which can cause some environmental issues including the accumulation, migration and transformation, and toxic effects of herbicides in agricultural soils. According to the characteristics of herbicide contamination and regional agricultural production, developing green and low-carbon technologies to reduce the ecological risks of herbicides to the soil-crop systems is a current concern in the ecological environment field. In this paper, relevant studies in recent years on herbicide pollution management in agricultural soils were identified and reviewed, the research progress and application cases of remediation technologies for herbicide pollution was analyzed and demonstrated, and future research and development tendency regarding the remediation of herbicides pollution was also prospected. Current remediation technologies for herbicides mainly include bioremediation technologies (e.g., microbial remediation, enzyme remediation, and phytoremediation), adsorption, and immobilization technologies (e.g., biochar-based materials). The bioremediation technologieswere rather mature and had been applied to the herbicide-contaminated soil in fields. Additionally, many successful bioremediation cases have been reported. Moreover, in order to enhance the remediation effect on herbicide pollution in agriculture soils, remediation technologies have been gradually developed from a single model to a coupled model with physical,chemical, and biological technology, which can maximize the synergy of the multi-technology application.

Geographical distribution of Ixodes persulcatus and associated pathogens: Analysis of integrated data from a China field survey and global published data.

The increasing incidence and range expansion of tick-borne diseases have caused global threats to human and animal health under the background of climate and socioeconomic changes. As an efficient vector in transmission of tick-borne diseases, a growing burden caused by Ixodes persulcatus and associated pathogens could not be underestimated. This study summarized the distribution, hosts, and pathogens of I. persulcatus, and predicted the suitable habitats of this tick species worldwide. An integrated database involving a field survey, reference book, literature review, and related website was constructed. Location records of I. persulcatus and associated pathogens were incorporated into distribution maps using ArcGIS software. Positive rates for I. persulcatus-associated agents were estimated by meta-analysis. The global distribution of the tick species was predicted using Maxent model. I. persulcatus was distributed in 14 countries across the Eurasian continent, involving Russia, China, Japan, and several Baltic Sea states, which ranged between 21°N to 66°N. The tick species fed on 46 species of hosts, and 51 tick-borne agents could be harbored by I. persulcatus. The predictive model showed that I. persulcatus could be predominantly distributed in northern Europe, western Russia, and northern China. Our study fully clarified the potential public health risks posed by I. persulcatus and I. persulcatus-borne pathogens. Surveillance and control measures of tick-borne diseases should be enhanced to promote the health of humans, animals, and ecosystems.

CD14+ monocytes and CD163+ macrophages correlate with the severity of liver fibrosis in patients with chronic hepatitis C.

Hepatic fibrosis is a crucial pathological process involved in the development of chronic hepatitis C (CHC) and may progress to liver cirrhosis and hepatocellular carcinoma. Activated peripheral blood monocytes and intrahepatic macrophages further promote hepatic fibrogenesis by releasing proinflammatory and profibrogenic cytokines. The present study aimed to investigate the role of peripheral CD14+ monocytes and intrahepatic CD163+ macrophages in hepatitis C virus (HCV)-associated liver fibrosis and clarify whether serum soluble CD163 (sCD163) may serve as a fibrosis marker in patients with CHC. A total of 87 patients with CHC and 20 healthy controls were recruited. Serum sCD163 levels were measured by ELISA. Frequencies of peripheral CD14+ monocytes and inflammatory cytokines expressed by CD14+ monocytes were analyzed by flow cytometry. The degree of fibrosis in human liver biopsies was graded using the Metavir scoring system and patients were stratified into two groups based on those results (F<2 vs. F≥2). Hepatic expression of CD163 was examined by immunohistochemical staining. The diagnostic values of sCD163, aspartate aminotransferase to platelet ratio index (APRI), fibrosis 4 score (FIB-4) and the aspartate aminotransferase to alanine aminotransferase ratio (AAR) in significant fibrosis (F≥2) were evaluated and compared using receiver operating characteristic (ROC) curves. The results indicated that the serum sCD163 levels and the frequency of CD14+ monocytes were significantly higher in the patients than that in the controls and positively correlated with liver fibrosis. The level of serum sCD163 was consistent with hepatic CD163 expression in the liver sections from patients. The frequencies of interleukin (IL)-8- and tumor necrosis factor-α-expressing monocytes were increased and that of IL-10-expressing monocytes was decreased in the patients. The area under the ROC curve (AUROC) for sCD163, APRI, FIB-4 and AAR was 0.876, 0.785, 0.825 and 0.488, respectively, and the AUROC for sCD163 was significantly higher than those for APRI and AAR. In conclusion, sCD163 may serve as a novel marker for assessing the degree of liver fibrosis in HCV-infected patients.

On the nature of the transition state characterizing gated molecular encapsulations.

Gated molecular encapsulations, with baskets of type 1, are postulated to occur by the mechanism in which solvent molecule penetrates the inner space of 1, through one of its apertures, while the residing guest simultaneously departs the cavity. In the transition state of the exchange, three pyridine-based gates are proposed to assume an open position with both incoming solvent and departing guest molecules interacting with the concave surface of the host. The More O'Ferrall-Jencks diagram and linear free energy relationships (LFERs) suggest a more advanced departure of the guest when bigger solvents partake in the displacement.

On the role of guests in enforcing the mechanism of action of gated baskets.

We designed and prepared a spacious and gated basket of type 2 (V = 318 Å(3)) in ten synthetic steps. With the assistance of (1)H NMR spectroscopy, we found that the pyridine gates at the rim of 2 form a seam of N-H∙∙∙N hydrogen bonds, thereby adopting right- (P) and left-handed (M) helical arrangements. The recognition characteristics of the smaller basket 1 (V = 226 Å(3)) and the larger 2 for various solvents as guests were quantified by (1)H NMR spectroscopy in CD2Cl2 (61 Å(3)), CDCl3 (75 Å(3)), CFCl3 (81 Å(3)) and CCl4 (89 Å(3)); the apparent guest binding equilibria Ka were found to be inversely proportional to the affinity of bulk solvents KS for populating each host. The rate of the P/M racemization (krac, s(-1)) was, for both 1 and 2, studied in all four solvents using dynamic NMR spectroscopy. From these experiments, two isokinetic relationships (ΔS++P/M vs. ΔH++P/M) were identified with each one corresponding to a different mechanism of P/M racemization. A computational study (B3LYP/6-31+G**//PM6) of 1 and 2 in the gas phase indicates two competing racemization pathways: (a) RM1-2 describes a pivoting of a single gate followed by the rotation of the remaining two gates, while (b) RM3 depicts simultaneous (geared) rotation of all three gates. The racemization of the larger basket 2, in all four solvents (packing coefficient, PC = 0.19-0.28), conformed to one isokinetic relationship, which also coincided with the operation of the smaller basket 1 in CD2Cl2 (PC = 0.27). However, in CDCl3, CFCl3 and CCl4 (PC = 0.33-0.39), the mode of action of 1 appears to correlate with a different isokinetic relationship. Thus, we propose that the population of the basket's inner space (PC) determines the mechanism of P/M racemization. When PC < 0.3, the mechanism of operation is RM1-2, whereas, a greater packing, represented when PC > 0.3, enforces the geared RM3 mechanistic alternative.

The entrapment of chiral guests with gated baskets: can a kinetic discrimination of enantiomers be governed through gating?

The capacity of gated hosts for controlling a kinetic discrimination between stereoisomers is yet to be understood. To conduct corresponding studies, however, one needs to develop chiral, but modular and gated hosts. Accordingly, we used computational (RI-BP86/TZVP//RI-BP86/SV(P)) and experimental (NMR/CD/UV/Vis spectroscopy) methods to examine the transfer of chirality in gated baskets. We found that placing stereocenters of the same kind at the rim (R(1) =CH3, so-called bottom) and/or top amide positions (R(2) =sec-butyl) would direct the helical arrangement of the gates into a P or M propeller-like orientation. With the assistance of (1)H NMR spectroscopy, we quantified the intrinsic (thermodynamic) and constrictive (kinetic) binding affinities of (R)- and (S)-1,2-dibromopropane 5 toward baskets (S3b/P)-2, (S3t/M)-3, and (S3bt/P)-4. Interestingly, each basket has a low ( ≤1.3 kcal mol(-1)), but comparable (de<10%) affinity for entrapping enantiomeric (R/S)-5. In terms of the kinetics, basket (S3b/P)-2, with a set of S stereocenters at the bottom and P arrangement of the gates, would capture (R)-5 at a faster rate (kin(R)/kin(S) =2.0±0.2). Basket (S3t/M)-3, with a set of S centers at the top and M arrangement of the gates, however, trapped (S)-5 at a faster rate (kin(R)/kin(S) =0.30±0.05). In light of these findings, basket (S3bt/P)-4, with a set of S stereocenters installed at both top and bottom sites along with a P disposition of the gates, was found to have a lower ability to differentiate between enantiomeric (R/S)-5 (kin(R)/kin(S) =0.8). Evidently, the two sets of stereocenters in this "hybrid" host acted concurrently, each with the opposite effect on the entrapment kinetics. Gated baskets are hereby established to be a prototype for quantifying the kinetic discrimination of enantiomers through gating and elucidating the electronic/steric effects on the process.

On the mechanism of action of gated molecular baskets: The synchronicity of the revolving motion of gates and in/out trafficking of guests.

We used dynamic (1)H NMR spectroscopic methods to examine the kinetics and thermodynamics of CH(3)CCl(3) (2) entering and leaving the gated molecular basket 1. We found that the encapsulation is first-order in basket 1 and guest 2, while the decomplexation is zeroth-order in the guest. Importantly, the interchange mechanism in which a molecule of CH(3)CCl(3) directly displaces the entrapped CH(3)CCl(3) was not observed. Furthermore, the examination of the additivity of free energies characterizing the encapsulation process led to us to deduce that the revolving motion of the gates and in/out trafficking of guests is synchronized, yet still a function of the affinity of the guest for occupying the basket: Specifically, the greater the affinity of the guest for occupying the basket, the less effective the gates are in "sweeping" the guest as the gates undergo their revolving motion.

Design, preparation, and study of catalytic gated baskets.

We report a diastereoselective synthetic method to obtain a family of catalytic molecular baskets containing a spacious cavity (~570 Å(3)). These supramolecular catalysts were envisioned, via the process of gating, to control the access of substrates to the embedded catalytic center and thereby modulate the outcome of chemical reactions. In particular, gated basket 1 comprises a porphyrin "floor" fused to four phthalimide "side walls" each carrying a revolving aromatic "gate". With the assistance of (1)H NMR and UV-vis spectroscopy, we demonstrated that the small 1-methylimidazole guest (12, 94 Å(3)) would coordinate to the interior while the larger 1,5-diadamantylimidazole guest (14, 361 Å(3)) is relegated to the exterior of basket Zn(II)-1. Subsequently, we examined the epoxidation of differently sized and shaped alkenes 18-21 with catalytic baskets 12(in)-Mn(III)-1 and 14(out)-Mn(III)-1 in the presence of the sacrificial oxidant iodosylarene. The epoxidation of cis-stilbene occurred in the cavity of 14(out)-Mn(III)-1 and at the outer face of 12(in)-Mn(III)-1 with the stereoselectivity of the two transformations being somewhat different. Importantly, catalytic basket 14(out)-Mn(III)-1 was capable of kinetically resolving an equimolar mixture of cis-2-octene 20 and cis-cyclooctene 21 via promotion of the transformation in its cavity.

[Differentiation of human embryonic stem cells to endothelial cells via improved three-dimension approach].

OBJECTIVE: To establish an improved three-dimension (3D) and serum-free approach to differentiate human embryonic stem cells (hESCs) into endothelial cells, and detect the endothelial functions of the obtained cells. METHODS: We cultured undifferentiated H9 human embryonic stem cell line in low-adhesion dishes to form embryonic bodies (EBs). After 12 days, EBs were harvested, re-suspended into rat tail collagen type I, and put into the incubator (37℃). After 30 minutes, EGM-2 culture medium was added to the solidified collagen, and the EBs were cultured for another 3 days to form embryonic body-sproutings (EB-sproutings). EB-sproutings were digested with 0.25% collagenase I and 0.56 U/ml Liberase Blendzyme for 20 minutes respectively, and the CD31(+) cells were sorted by FACS. The endothelial functions were tested by Dil-ac-LDL uptake assay and tube formation assay. RESULTS: This approach raised the efficiency of endothelial differentiation to 18%, and also avoided the contamination with animal materials. The obtained hESC-derived endothelial cells (hESC-ECs) had the similar pattern of surface biomarkers as human umbilical vein endothelial cells (HUVECs), and their endothelial functions were confirmed by the uptake of Dil-ac-LDL and the tube formation on Matrigel. CONCLUSIONS: The improved 3D approach can enhance the efficiency of differentiation from hESCs into endothelial cells. Furthermore, serum free differentiation system may be applied in future hESC-based therapies for various ischemic diseases.

The role of chirality in directing the formation of cup-shaped porphyrins and the coordination characteristics of such hosts.

Cup-shaped porphyrin 1a has four norbornane rings for encircling space and this type of host could be of interest in supramolecular and catalytic chemistry. We used (1)H NMR spectroscopy to investigate the acid-catalyzed (pTsOH in CHCl(3) and TFA in CH(3)CN) condensation of racemic, enantioenriched (80-85 % enantiomeric excess (ee)), and enantiopure (99 % ee) pyrromethanecarbinol 7 into 1a. We found that the oligomerization of racemic 7(rac) would give 1a-d in the ratio different from the statistical one, though a minuscule quantity of 1a (<5 %) formed. The oligomerization of enantioenriched 7 (80-85 % ee), however, led to the formation of greater amounts of 1a (31-47 %) along with other stereoisomers 1b-d. Importantly, pTsOH catalyzed the conversion of enantiopure 7 (99 % ee) into 1a (>95 % diastereomeric excess (de), 25 % overall yield) in CHCl(3) although prolonged reaction times or greater concentration of the catalytic acid gave rise to 1b-d at the expense of 1a. The metallation of 1 a with Zn(OAc)(2) led to the formation of Zn(II) -1 a and we used computational (DFT: RI-BP86/SV(P),TZVP) and experimental ((1)H NMR spectroscopy) methods to study the partitioning of smaller N-methylimidazole 13 (94 Å(3) ) and bigger 1,5-dicyclohexylimidazole 14 (268 Å(3)) between the inner and outer side of the host. We found that bigger 14 was mostly encapsulated (90 %) inside Zn(II) -1 a at 298.0 K, whereas smaller 13 would equally partition between the two sides of the host. Furthermore, the out/in equilibrium was, in the case of 14-Zn(II) -1a, favored by entropy (TΔS°(out/in) =3.5±0.1 kcal mol(-1)) indicating that perhaps differential solvation of the coordinated ligand assisted the encapsulation.

Controlling the dynamics of molecular encapsulation and gating.

This critical review describes mechanisms by which guest molecules enter and depart molecular capsules. The discussion focuses on presenting gated molecular encapsulation, i.e., trapping and releasing of guest molecules at rates that are controlled by conformational changes in the host's structure. Developing quantitative rules that describe the gating are, at present, a matter of scientific curiosity but could play an important role in building more effective catalysts, drug-delivery devices or membranes (105 references).

Gated molecular recognition and dynamic discrimination of guests.

Some highly efficient enzymes, e.g., acetylcholinesterase, use gating as a tool for controlling the rate by which substrates access their active site to direct product formation. Mastering gated molecular encapsulation could therefore be important for manipulating reactivity in artificial environments, albeit quantitative relationships that describe these processes are unknown. In this work, we examined the interdependence between the thermodynamics (DeltaG(o)) and the kinetics (DeltaG(in)(double dagger) and DeltaG(out)(double dagger)) of encapsulation as mediated by gated molecular basket 1. For a series of isosteric guests (2-6, 106-107 A(3)) entering/exiting 1, we found a linear correlation between the host-guest affinities (DeltaG(o)) and the free energies of the activation (DeltaG(in)(double dagger) and DeltaG(out)(double dagger)), which was fit to the following equation: DeltaG(double dagger) = rhoDeltaG(o) + delta. Markedly, the kinetics for the entrapment of smaller guest 7 (93 A(3)) and bigger guest 8 (121 A(3)) did not follow the free energy trends observed for 2-6. Thus, it appears that the kinetics of the gated encapsulation mediated by 1 is a function of the encapsulation's favorability (DeltaG(o)) and the guest's profile. When the size/shape of guests is kept constant, a linear dependence between the encapsulation potential (DeltaG(o)) and the rate of guests' entering/departing basket (DeltaG(in/out)(double dagger)) holds. However, when the potential (DeltaG(o)) is fixed, the basket discriminates guests on the basis of their size/shape via dynamic modulation of the binding site's access.

Tuning the rate of molecular translocation.

Gated molecular baskets can be functionalized to tune the conformational dynamics of the gates, installed at their rim, and thereby to adjust the time that a guest molecule spends inside their cavity.

Four-state switching characteristics of a gated molecular basket.

The development of working molecular devices relies on the ability to extrinsically modulate function via structure. We have found that gated molecular basket 1 can be reversibly interconverted among four unique structural states (see above). Controlling the relative population of these states, the recognition characteristics of the basket can be finely tuned.

Remarkable bromination and blue emission of 9-anthracenyl Pt(II) complexes.

Contrary to expectations, molecular bromine addition to trans-Pt(Br)(9-anthracenyl)(PEt(3))(2) does not result in Pt oxidation or Pt-C bond cleavage but rather in selective multiple bromination of the anthracenyl ligand. The resulting complexes are highly photoluminescent in the blue region due to triplet-triplet annihilation induced delayed fluorescence from the anthracene.

Encapsulation of guests within a gated molecular basket: thermodynamics and selectivity.

Molecular basket 1 has been designed to contain a set of aromatic gates, each with rotational mobility restricted via intramolecular hydrogen bonding. This structural, yet dynamic, feature of the host has been revealed to permit the formation of a transient enclosed space capable of containing haloalkanes, whose size/shape, electronic and entropic attributes contributed to the thermodynamics of binding. Markedly, the basket is capable of mediating the trafficking of a broad range of molecules.